Telephone system



' Jan. 13, 1931. L. L. RUGGLES TELEPHONE SYSTEM Original Filed Dec. 2, 1927 5 Sheets-Sheet 1 Jan. 13, 1931. 1 RUGGLES TELEPHONE SYSTEM original Filed Dec.

2, 1927 s sheets-Shogi 2 les .Lennard L E Jan. 13, 1931. L. L. RUGGLES TELEPHONE SYSTEM s sheets-sheet s original Filed Deo. 2, 1927 llm J we Lonard L.

*Patented Jamie; 11931 'i LEONARD n f RuGeLiis, on -W-Hi/imon L iin-:incisi Assienon To' Hoi-,13mg COM;

PANY-,oF-fKAns-ASJGHY, MISSOURI,A conronmfronfoij pnLAWAnE Y TELEPHONE Appli'iv me@ member' 2, 1927i Serial Nol, lfeerema? 5s 1930- he present inuention'reletes to telephone Systems lin"general; but-ie concer-ned' more' particularly' with Senn-automatic telephone systems of the remote Controlledltypeg' and esp'eially'with semi-automatic lnegnetoex changes. Y In my application', Serial No. 199,391.7, filed j lune 20.11927', ftliere is disclosed e fseiniauw Itoniutic telephone s ysteni of thel above t'ypelf lnfvthie p rior s'y'steni,theinitiation )izueall`isV A Reflected ,responsive 4vtof the' operation of'fthe l .hand generator :it afealling stetiongand 'theV olering out off" thef Connection after liyghzts.;

b'eenf'setup 'bythe' Semi-automatic operator' Y 3:11-througli'theeutoniatieswitchesvie" accom-" p lishedwheii ringing-current' is'trzinsrfnittedf;

' wey,` the v Suli :e 'cribers i linee-are 'Operatediii'if exactly the stime mnner 'es though they are y t receivingpurely Innu'gil Service, eJnClnofOpv-` nient has been modified to vthe"`eX`tent that only the initiaton of the 4@all 'isfl dependent v=up`o`nlringing:current fromv the ealliii'gi5eta-i tion," a Slight holding Current being. p r o' vided` fromrthe "exeh'angef'over they "calling lineto holdthe connection under the control of `the [Callingy station after 'the 'connection haer-been. Seti'up'. yj-It;iS"zicordingly'fin obli@ jectof the invention vgto proviclevsuitxble 1 f Y holding circuit-s euch' th'atthe 'tying up of Vequipment 'due minimized. B-'yl this-finethod of rele'e'si'ngzthe io'nnetions,V f the Vililieulty encountered in 1 Y if' the':abovenientioned prior syste'rndue to the?V I hais been obvietedi f i Aeature of the invention-hee inthe zn'-4 pli'el over 'one Conductor oftheoalli'ngvline j through thefealling Station andf'baolto the vezygf'zhann'ge over' the otherfeonduotori o'fjthe Grilling `linerto theholdingreley :in thefezr-jV change; sothet van accidental'groundrfcom` Y neetion will'not cause @Connection to'be held genei'zil; 'i' -in substituting "leycontrolledjf locking andv slow'fa'ctingl relays: to' perform "tl-1@ @Peri-ref emmen the @renting vtini,andi still anothen-,speeial"operation si ne" nm up, ves would be the csiiseiifitheholdingleurfvr rent' were'V 'Supplied `through :L holding rely 'to-"thefline @t the exchange.

1 ZKlnotlier obj et of'tliefnvention is'the pro? duction o inev/and iinprovedeiiouitj arrangeinents'at the Switchboard)Ofthefoontrolling operator? 'in the operatingcenter Wherebyehel eginhendleth'eCalls'inorefreadily -nd Withles Y lziborfper!Call. lhis improvement Aoonsists, Y l

and time "s'Wit'ohing functions ziutomatieall'y 4 s 'rfrlned and-'timedv 1A?-frthefobjeetof ie in the rengeinentsf-Whereby supervieofry Vswiteh is provided individual to ,thf'e 'single rroperating trunkfoonnectin'g theoperatinggeenterwith the.'Seinifautonitio'egihnge. `This isuperl' 70v a mechanical? gsteplby-St'ep' rot'eiry-jtype finden runhe bied-g of the invention is lng-@h l 1J-@vision er Suitable;arrangements whereby eonnetorto'Whie. t connection during the' supervising: operegj the Vepplieaitioni (3i-ringing ymirrorit toanyfl 65 Q produtionfof fnewnnd'ihproiiedicirouit alf-'.5 f

to which the operator has eXtended a connection through the 'supervising switch..V

There are other objects and features having to do, vtor the most part, with the various de-Y tails involved in carrying out lthe objects set forth above. j The various'objects and fea-V tures of the inventionwill be understoodbetter upon a further perusal of the specification in connection withthe accompanying drawings comprising, Figs. 1 3. Referring now to the drawings, they show by means of the usual circuit diagrams a sufficient amount.

of equipment in a telephone system embodying the features ofthe invention to enable the invention to beundeistood. l

' Fig-,1, shows certain equipment at the controlling position at an operating center. From this position, the switches infseveral small semi-automatic exchanges may be con- Y trolled. This drawing shows also an operat-k ing trunk connectingt'he trunk circuit TG1 less there is moreltraliic than one operator can handle,-in"whicli 4case two for more con-1 trolling'positionsmay` be provided.`

Fig. 2,showsjthe trunk circuit TG2 termi nating the semi-automatic exchange end of the operating trunk and having associated therewith the -finderF and the supervising switch S. .Y e

Fig. .3, shows the connector Ci'a'ndfapor-fV tionofthe associated'master switch, as well as Athe line switch of thelline of sub-station AV andthe line of sub-station B. vThisY connector is one otra groupfof tem-for eXaiiip.le,-pio vided to handle the local calls.. .The -toll connections oetweenthe semi-automaticeX-V change and other exchanges are handledby Va toll v operator in the semieautoniaticfex- (':hange overtoll lilies (not shown) by suitable toll .switches having f their banks connected in multiple lwith'theib'ank of connector C and the otlierlocal connectors. f Siiicethe toll equipment 'forms nopart' of the presentan ventionit liasiiot' been shownj liereinggTh'is Y en equipment, however, may bemoreforless siinilai-,to the toll-equipmentshowii in the above-mentioned prior. application, exceptl thatgitinay `be v.Teiyniiuch simplified owing to tlie fact that the supervisingoperations in the. present disclosures are taken'y care of b v the supervising switch SS, Figf, Yinstead of over the toll lines and through the toll connectors as in `Vthe prior application.`

1 *"flhe connector C Fig. 3, and the supervisingswitch SS `Fig;,Qareeacli lof the usual vertical" and rotaryftype, having back con- Y taets arranged inten'horizontal levels. of ten contactL sets per level. The code machine in- `ing 305.

dicated inFigl 3 contains the contacts shown,

which maybe operated by any well known or desired type of cam arrangement. The

vcani, device causes the contacts to deliver Vthe desired distinctivecodes tothe various conductors extending to `the vbanlrof the code ,switchand to the banks of the other code switches in multiple,rthe pickup conductor Vbeing grounded momentarily before the starting point.ot-"the` codes is reached and the stop conductor being grounded momentarily after all the codes have been transmitted.

The apparatus having been described in Igeneral, a. detailed description of its operation will now be given. For this purpose it will be assumed that the subscriber in substation A; desires to Vconverse With a sub-` scriber at sub-station B.

@all from sub-station A to sub-statioi- B After removing` his receiver, the subscriber atsub-station Apperates the pus-h button on i his `telephone connected in the generator bridge so as Yto condition the .line circuit for signallingtheoperator, as in modern magi neto piaictiee.4k The operation ofxthis` p usli Ybutton resultsfin the disconnection of. the

generator dfrom Ythe usualbridge and in the grounding" of one terminal. -The result is that the Yringing current is transmitted from ground over vthe -lower talking conductor` only and it operates the line relay 302 of the lineswitch LS, whose upper Winding is'con-V nectedbetween the lowertalking conductor and ground'through the cut-ofiq contacts 303.

Upon operating, line `relay/302 locks itseltl its lower contact-sito ground through contacts 306 in a circuit including its Ylower winding, and atitsuppercontacis it closes a 'circuit for the pull-'down winding 304 ot thelineswitch, ,whichu circuit includes the open main, conductor 361-. Responsive to the closureof the circuits through the pull-down' winding 8014, thef'pull down armature 30]" is operatedto complete the connection to 'the preselected connector C, and the cut oli contacts 303 :areV opened' by. the lassociated arma ture to disconnect the upper winding koii relay 302V froiirY line.

ture VB O'yand Vthe contacts are" forced into engagement 'to complete -the Y cire-uit. the groundV potential on lrelease trunk conductor 316 'of'theconnector Gg vthrough upperwindr ing of relay32l and oilnorinal 328, is placed cn the private-normal conductor 301 oi the .lineswitchV toniake the calling line busy in the banks of the Yconnectors and to close a circuit-'through the cut-off and holdin windwinding is suflicient to maintain the line- The current flow througi Vthis Then the lplunger A(not 5 shown) is operated by the pull-dowii arma-VL ias switch in ianoperated position. Just as the armature 307 completes its stroke, it sepa- 'rates the [contacts v306,: opening the v locking Vcircuit ci"l line relay-302,Vv whereupon'rrelay @meer v relay operates through itsY upper 'Wndngjln' serles Wlth thecut'eof Wmdn'gBOtfof the" end places grol'ud 'ouwh'oldg conductor 348,y

end et ils )errer 'i111et@feitz ereuhd's 'the finder-start 'conductor' 271,' at the samen-me v through' the upperfcorrtectsolf relayY 7323i;k through its,mddleupperfcotact lo the top n f cofrid'uctor ,217,6I in they benk of the fuderf?,

armature, .'.storfrnri ,the Opration; 101- ztile v'lrldeln lt` rte middle lower armature arid at' #u f. y y n annefrank,

Vconductorv a,'locking circuitvv 's' prepared at its inner lowerfcoutacts.'@Agfafurther? vresultjof the operetlou'oolfrela f V' o imlVhe'n relay 202 operated-"itlopeelthe' cl 'y coming? .titllilnflj;conc

' Y 210 oitlrellhder me that@ @ellis waiting I ,y A o peneth'e "cuitthrouglr" the j pull-dorff" Winding l 3045; Ae kllefurther? refeult; "the operation of the lineswftch,`I ground' ifs placed et thecontactsthereoforv the holding conductor A317', 'causing the. nde-"sixY terswitch', under thetrol 'fte tart releyf l Sci rillothertrunky line. As a `further resultof thegroundllg of forth@ :lower'Winding-of.relay 321, which line-switch and' c'losee tlleflockingvr circuiti? movesVK ground *from` V3 llease conclue so @sito prepa-re` thoefswtchv for'o'peration,t

,carrying the' :Stopping,r ground" potentiel from ithe 'comnor grounded'v c'ol'o'duc'tor 278 e e; circuit vrelay 201 the .test wiper 213y 'yyhe'z'A the latterencouuter's from the connector C.

culti? ofy operatingl magnet 208 Yet itsl lofv'e its upper armature,` relay 202 connecte thefuf;

eters "wglpere 209 Y* 'l' A rele-y j 204; 203, therebll. v

-hll ouglrthe i 'ht hd windings,

the operel wipe; l..

13o fr' Y vshifts theoperating circuit from the vertical y Vie spending contacts on relay 323 and the circuitY magnet to therotaryvmagnet 334. Y l Y lil/Then, theoperatordialsthe"second digit inthe number, Vtheimpulses are transmitted to the rotary magnet 334 oftheconnector C through contacts kof relays 322,323, and 325..

The rotary magnet 334 responds by rotating the'wipers 336--338 vinto engagement with.. tliebank contacts in Vwhich the line of substation A terin'inates. `Slow-acting relayf324 is energizedk in multiple with magnet 334 throughout the rotary operation.V At its upper armature, relay 324 disconnects test wiper 337 from thetest winding of relay 323 and connects it insteadthrough contacts of relay 325 to the winding ofbusy relay` 323, and'at itslower contactit shunts the correofY the.` rotary magnet iso /as to maintain its own circuit and that oit rotary magnet 334 intact in case' busy.` relay-V323 energizes 337- during the rotary` through test wiper movement. y

From this point the. operationV depends PYuponwhether the line of sub-station Bis busy or idle when thel call is made. Assuming first that the line is vbusyjbusy relay 323 is 'ener-VV gized, when the wipers comete rest, through a ground kpotentialon the testcontact encountered by test Vwiper 337. In, this case, when relay 324ialls back' it Ycompletes at theV normally-closed contacts V contrlled by its upper armature, va circuitthrough the inner Vupper armatureof rel ay 323 for locking relay 323 to the locking conductor 343. Vlith relay 324 deenergize'd and with relay 323 operated, the operating circuit is openedat theinner lower contactsot relay 323. At lthe lower y contacts of relay 323,the .busy-tone lcurrent is placedV on theealling .line from the. cemmon busy-tone conductor 365V through contacts of reiay 325. Upon hearing the 'tone'produced .by the flow current, the calling subscriber Y isv expected lio-replace hisreceiver and call later. L

v Assuming now thatvthe line of Ysub-station V'B is idle when called, busy rela1y'323 is not operated when the wipers Vland-on (the con'-v tacts of the calledV line Vand'switching relayj 325 operates upon thev falling back 'of'lsl'ow acting relay 324 to seize the called line.' Relay 325 operates through its` lower winding, whose lower terminal isconnected tothe grounded 'conductor 343 'through .contacts of `busy relay 323, and whose,upper terminalI is connected to test wiper 337 through con-V tacts Vofrelay 324'. The circuit Vto battery is completed over the .privatenormal lconductor through the cut-off winding wof the lineswitch on the called line,which winding corresponds4V to WindingY 305 of the'lineswitch LVS. VvThis .M no

y cut-oft winding energizes sufficiently 'todisV connect the line relay, but not suiliciently toV operate the lineswitch. Upon-operating, re#

,lay 325 closes av locking circuit for its .upper code switch.

' mesme winding to the grounded conductor 343 at its Y i inner upper contacts; at its middle upper contact's it places ground directly on wiper 337, thereby supplying a more direct guarding potential to the test conductor of the called line at its` inner lower contacts it transfers the operating circuit from the rotary magnet 334 to the operating magnet 341Y of the code switch; it opens a point in the circuit of busy relay 323 at a pair of upper contacts; grounds Ythe negative tallingqwiper 336 at its upper contact to afford areturn path for the ringing current; opens a point at its lower contacts in the busy tone circuit and prepares a ring-bacltone circuit` through condensers 335; land at its middle lower armature it,

closes a point'in the energizing circuit ot pickup relay 326. v K Y `W'hen the operator dials the stations digit in the desired number, the impulses 'of current are transmitted tothe operating magnet 341;,ot' the code switch. When the operating magnet 341 responds, it sets the wiper 342 on the bank contact corresponding to the code as-k and closes a further point in the circuit ofv `pick-up relay 326, at the Vsame time opening the operating circuit at itsinner lower contacts to prevent further Vmovement of the.

When the pickup conductor 364y grounded by the code machineprior to thebeginning of the code period, a circuit is closed through contacts 'of relay323 and 325 `toil pick-up.. relay 326, lwhereupon pickup relay 326 operates and locks itself to conductor 343 in the usual manner. Pick-up relay`326. alsoprepares a circuit for stop `relayi327 at its inner contacts and at itslower VAcontactiit connects wiperv 342 of the code switch tothe positive wiper 33S so as to atlord a path for transmitting the ringing current to the Ycalled line.` Asa result, the Vcode se-U lected by the'code vswitch isnow transmitted over the called line and operates the various ringers onthe line, they small condenser 335 permits a small amount ofiringing current to. reach, the calling `line through contacts of relays 323 and 325 Vso that the' calling subscriber is notified of the signalling operation. @After thefcode has beentransmitted, the

stoppconductor 366 is grounded by the code Y machine, closinga circuit through contacts Vof relay326 for stop relay 327. Relay 327 operates and-locks itselfto conductor 343,' at thesame vtime opening ther-inging circuit and .completing the talking. circuit at'its V.upper and .lower armatures. g l Y i Asfsoon' the subscriber at substation B responds'to'theringing off'his hell by remoy ing his receiver thetwo subscribers may con- Vv'e'rsejwith eachother in the `usual manner. ,"After having dialled al-lthe digits in the number, the i @peratorV frees lier'coinrnon equipment from'the'operating trun iat the trunk circuit TGlrhy momentarily depressing l i tlierelease key RLSE;A VWhen the release key 1oy operated, it Jcloses a circuitthrough con- "tacts of relay 101`for the'lupper winding of relay` 104.1 i It `will be lnotedthatthiscircuit v.is takenthrough'contactslo'f slow-acting relay time thereafter so asto yprevent premature,

rrelease in case the operator sl'iould' operate 101, which is operatedthrougli oilfnorinal Vcontacts of the calling dcviceas longv as the callinga vdevice is olf-normal and' for a short her release key during Ior too soon afterthe last return vto normal of' the callingl'device. When relay 10.4" operates it closes af` circuit i in parallel with its upper winding'through Vcontacts of the loclreduip relay k10G V'tor the slow-acting' relay l105.` Relay 105joperatesand closes a lockingfcircuit Vfor the" lower y windingofrelay-lOllthrough the inner lower contacts of relay 1041, at the Sametime opening the locking circuits of relays 102 and `1016. RelaysA 102 and106 now fall back and' disconneet` the'operatos head set and' the' calling deVlCe'roni thetrunk circuit. Relay 10G also opens the circuitko'l'l theslowacting relay 105 so as start the Irelease'olf this relay'right er away regardless of whether the operator ,permits the release key to restore immediately or, fnot. It will'be noted thatvrelay 1041 at'itSllPv per and lower contactsopens both operating conductors so that relay 103 is notreoperated when rrelay 102jre'stor'es. Then relay"1105-y falls hack .it'opens thelocking circuit o ithe y lower winding of relay 104 'with the result that relay l0-lnow falls back andreconnects relay 1,03; to theoperating conductors providingi'he operatorhaspermitted the release key operation to he hereinafter descrihedto take place inthetrunk circuitrTC2; Fig. 2. y

,Y Referrintg now 'to vFigf2, when line relay 201i y,falls back responsive to .the lforegoing Qopening of the 'operating ,circuit at the upper and lowerfcontajcts ofrelay ,Fig 2,

j it again place'sgroun'd on the operating con-- 'ductor 27 5 throughwiper 212,-hut thisyfdoes not result in ,further Q'peration lof the code.. swtclnlig; because relay 323 has the Operl ating 'circuitopen atlthis tinie'at itsinner 'v lower contacts. Aj'yinoment flater, the slow Y acting lrelay 205.falls`hack and opens the operating circuit at` its. lower armature, at

the same the ycircuit of slow actingrelay`206 and the circuit of relay 202. Relay-aoc isfrenclered slow acting SQ-,aste a1- 1ow-relay2202 `1.tofal1 back l andV per-mit! the i "finder to advance@ a dierent; ppstial. in

case"` another' `call is waiting, regardless 0i whetheror 'not the connectorlG, Figk 3, has

ungrounded yitsstop conductor 276;at the upper contacts oi' relay 323. i It' another call is waitingystarit.conductor 271gis 'grounded and `operating magnet" 208, lwider the control f `of'lrelayg1201;starts advancing the finder agaiulf'Slow-acting?-,Qrelay 205, however, is

arranged to bei ,only slightly slow, so Athat itl falls .back almost immediately a1`i dj recon .nec/ts stop wiper 213 to` stop` relay l202rhsoas to enable rt-helinder to stop on the ncxtfcontact set "incase thenext. connector is* one on l ywhich ithecall ijswaiting. If, onA thefotlier `hand,no call is waiting, therinder F doesnot `move ati this ktimeybut, standsonthe lconnector last used untill 1U Other lC2111 comes in.V

Referring agantojthe"established connection it will-'he noted that' va'multiple holding bridge is established over the calledline so thatvthe connector. CMwill remain operated until.1 hoth subscribers Vreplace their receivers. .@I desired, talkngfcondensers could `loe inserted between the line wipers 3.36l and 338,

and the'point in the talking connection to which-the impedance-coil 319 and'holding f relay 320a`re connected. l

When both euhscribers have reialaced their receivers, `the Currentllow through` impedancefcoil :319 and relay 320, ceases, and Irelay 320 4falls hack, removing groundfrom release trunk conductorl.; `'Vhenthie occurs, the cut-off vwinding'305 of theflineswitch LS deenergizes and pernjiits thelline switch to restore;` `When the `line switchiestores, the

fico

ground potential is removed from holding .conductorfl rendering the connector idle again in the bank votfthe master switch and imloelcing-release relay 321jofthe connector.

'Relay 321 now falls back' and atits inner upper` armature it disconnects ground from holding conductor 343 and places ground ou, conductorq27 l l viroin conductor ,55143,` the locked-up Vrela-ys 325, 326, fndlg'fall hack. yThere]ease `magnet 340z "of the, code switch loperates througlisthef middlefupper contacts of yrelay 323. and restores "theY cofde'switch Ito normal, rihereupoirthe olfnormal contacts 339 of the code switch open tliecircuitof relay 323,

permittingVK relay 823 vto yfall back and open the circuit of release margin-313340. .The circuit of release-magnet 332 is' opened at o-norinalcontarts Theconne'ction isnoW released andthe ap- Vplara-'0,11s inyoly'le'dftherein is conditionV for Ifurther 'use.

.t When ground is removed Anet lnolpv. operates through .oi'ri1iiiialcoh-- tacts y530rom grounded'conductor 274; and hresterestlie connector tonornial, and releaseg Release after an error Assuming now that the operator at'the operating center is setting :the connector C and Aio discovers'that she has dialled a number other than that called for by the calling subscriber, f

she may release the connector@ without releasing the callingline switch, the line switch LS orexainple, by operating the specialreleas'e'liey, Fig. 1, associated withthe calling device.V When this Vrelease key is thrown,

Vthe lower operatingconductor'lisA opened,

whereupon current ceases totlow through the lower winding of differential relay 203, Fig. 2, line relayr204 being maintained operated Vover the upper operating conductor.

Relay 203 now operates and places ground at its lower contacts on release wiper 211, eX- tending ground over conductor 274 to the release magnet 332 by way of off-normal contacts 330 and to release magnet 340 of the codev switch by way of the middle upper con-y tacts of relay 323, incase the code switch has been operated. This restores the connector' to normal mechanically, without removing ground from conductor 316 to permit the calling line to switch to release. At the'contacts of the release magnet, the ground potential is removed from conductor 343 so as to permit any locked-up relays to be restored.l

When the operator has held thespecial-re lease key operated long enough to permit the releasing operation to be completed, she restores the key, whereupon the differential relay 203, Fig. 4, falls back again and removes ground from the release conductor` 274.

Master-switch protection l In order toprevent the master switch from 'operating unnecessarily in case all of the connectors have been seized, the guard relay 368 is provided to disconnect the start relay 367 and v to prevent operation of further a line switches by removing battery from the conimon operating conductor 361.v This relay is normally energized by ground potential supplied by each of the connectors, ground potential being `supplied to conductor 363by the connector C through contacts of relays 321 V'and`327-` Relay 321 it will be recalled energizes as soonasthe connector is seized. Now, as soon as the last connector is seized, therey lay correspondingl to relay 321 removes ground at/ the last Vpoint from conductor 363,

permitting stop relay 363 to fallback and render the master switch inoperative until a connector becomes idle, at which time ground is restored to conductor 363.`

AZZ-,truncS-ibucg/ signalling f Arrangements have been madefor signal? ling the operator incase all trunks accessible` to the line switches and extending to the connectors become busy, as some of these connectors mayV be indicating busy when, as a matter of fact, they are not being used any longer. line insulation or to subscribers having neglected to replace their receivers after conversation. It is obviously undesirable to signal as the last connector has been taken for use because the signalling operation would Y inter.-

ere with the handling of the last call. Furthermore, a connector may become idle and be released before the call has been taken care of. At any rate, the apparatus for signalling the operator that all trunks are busy does not come into playuntil the last connector has been operated.

yAssuming now, that all connectors are busy except the connector C and that the connector C is seized by the lineswitch LS Yin the herentofore described manner, the inaster-switch-stop relay 363 falls Aback as soon as relayV 321 operates upon the seizureof the switch. Then, when the operator has repoint from conductor 277 when pick up relay 326 operates after the connector C andthe associated code switch have been set. lVhen ground is so removed from conductor 277, the all-trunks-busy relay 232, Fig. 2, falls wiper 245 or' the lsupervising switch, at the same` time at its inner lower armature placing a busy tone on the upper wiper 243 of `the supervising switch through contacts oi the alarm relay233. inner upper armature, closes a circuit for the` upper winding of signal relay 234. llelay 234 operates and locks itself to ground through contacts of oil-normal relay 231, at its inner upper'c'ontacts. armature, relay 234 opens a point in the circuit of the associated release magnet; at its inner Vlower armature it places groundon start conductor 271; and at its middle lower armature it grounds the test conductor eX-r p usual manner.

a When Vthey operator responds, she hears, y through the wipers 209 and 210 of the inder fF, the busy tone placed on the Wipers'of the [supervisory switch SS. i The presence ot this busy tone on the operating trunk indicates to the operator that all trunks are busy, and

They may be held up due to poorV the operator that all trunks are busy' as soonV sponded to the calland has operated the. connector, ground is removed the last` back and, at its lower armature, grounds Relay 232 also, at itsV At its upper she proceedsy to superi'fisel the connectors and* y' insane' l l and out which, fR-DIY, 'are operated' and'glt infuse. Y l K `Upon hearing the busy tone on thefoper 'ating ytrunk',the operatorl dials. t'liel digit 9 and proceeds to supervise the various-.connectors. -f

wilma@ diga. 9 is aimed, the einempulses ofcurrent transmitted by line lrelay 204 are 'received by vertical magnet241 of the supervising switch Ythrough Lwiper 212, on its last Contact, and the ofi-normal contacts 238 and series relay 235. Vertical magnet 241-responds by raising the wipers 243%245 opposite the .ninth-level of bank contacts. 'Duet-o the combined action .of ofi'- ing series .relay 235,]tlie operating conductor is malntained in connection with the vvertical f l ,20 vmagnet untilithe end `oit-the vertical 4movenormal contacts 238 ai1d239, and slow-act 1nent,1whereupon itfisV transferred vto rotary l magnet 242:#*Uponthe closure of ofi-normalv t from the talking conductors.

contacts23j?, oli-normal relay V231: operates v .c and ungrounds't-he 'start conductor `and the 25 associated stepconductor at its middle lower and lower armatures, respectively, and atv its inner lower armature yit r'eoperates relay`232 sogas to remove the v,busy-tone coi'xnections 1 Having dialled'thedigit 9, the-operator now dials the `digit l, whereupon the' wipers" are advanced one step lby rotary magnetf242 to make connectionwitlithe/first connector,

-it being assumed thatfthere are ten'iconnecr tors or less,- It gwillbefinoted:that the first set of 4bank"contacts inthe ninth level are 'l Connected t0` the GQnCluGtors-.272 and .2,73 entendingto the Connector! C. Accordi' i.ngly,ftheoperatorlisfenabledto. listen to the conversation yin case there is `oneinvolving this connector.

Assuming thattlie operaton upon 'listent ing in;` discovers that'there isrno conversation being carried` on over this connectorf she frelea'ses'f the; cOnnector by throwingv herV special-release key, unbalancing the difieren-IA tial Arelay 203. Differential relay 203 re spends by grounding wiper- A245.,- rlhe ground potential-.placed on this wiperlis transmitted to thelower conductor 318 offthetrunk yline extending to theconnector-C, shuntinggthe holdingrelay, 320, whereupon this'r'elay falls back-and ,permits the 'connectorY to release in the -f,hereintofore-described2 manner.I L y Y In order to supervisethe-nextronnector,

the` operator lagain dials the digit 1 ,1whereupon the switch in addition, the falling `back-.of relay2O6j results inthe ungrounding of locking con- .y 65

ductor 247, otifnormal relay being oping the Aconnectors. .j

eratedthroughwoti normal contacts`237 of this time;4 vWhenconductor 247 is ungrounded,.relay 234.j:fralls ,back and closes at its upper armature` 'ai circuit for the release magnetthrough contacts of the offsnormal v.rev lay, whereupon the'su'p'ervising switch is-re ystored to normal inthe usual manner. y

Y In casefthe operatorffound all ofthe con` `nectorslbeingrusedafshe ofcourse has not re-. leased1 -a`ny ofwthennjand the all-trunksbusy: .condition vcontinues".after she'has cleared' outy her equipment., Infthis casefrelay 232 falls back andv again operates 234 .whereuponthe 'l operator `is again signalled. The operator may ignore this signal for an interval in this.V

case andV74 waitv awhile Supervising alarm signals f i ber: ofV 'alarmsignals to indicate when ab-V normal'conditions exist, such as the blowing .oi' fuses or vthe operationof heat coils on the main frame. Arraiigements have been made in this case' to use the same supervising switch SS,fFig.`2,jtosupervise alarms. For

Inany exchange there isprovided a num- -v the'purpose of illustratinghow this is done,

a heat coil v255:-l1as been shown within the dotted` rectangle labelled alarm circuit. When an abnormal current flow occurs inthe associated line, theheat coil is permitted to turn due to tlie'melted. solder within the hea-t coil, permitting contacts 253and 254 to'close.

Assuming-'now that the lheat coil 255'has operated andpermittedthe contacts 253 254 to close, contacts 254preparea signalling circuitfromthe ringing lead throughtA the reducing condenser-255 to the associated contact .in theI tenth level of the lbanlz'lof i wiper'243. j Contacts 253: ertendjaJ ground- .l v potential` through contacts of relay 25lfto conductor 246, yai'idclosjing a circuit through contact-s` ofA o-norinal relay 231 torjthey alarm-start relay 233. `Relay' 233l operates and closes a circuit lfor relae234 in orderY to cause'fthe finder Fito advance.;tothesuper-`r yising` position, at the Sametime placing ground on w1per245 and a ringing toneon wiper'243.-l yResponsiveto the operation of v relay 254 the'inderfl Eadvances to supervise; infgfposition :in thejhereintofore described mannerV and the operator, upongresponding hears Ytliefrin ging tone placed. on 'by relay "233, andk knows Vt'hatan alarm conditioneirists. f'

In order to determine just what alarm con: dition exists, the Aoperatordialsl the.y l digity (l and then proceeds to operate the supervising switch: step wby l"step iacross the tenthlevel operates, relay '233.is` disconnected and. falls,

back to Vclear thetalling conductors..

-As soon as thefirst contact in the setl is reached by wipers 24S- 245, the ground p0- tential-placed one-wiper 244y through the con- Y JtectsofirelsyQand PaSSG throughfthg before again supervisv 'l bankcontact onfwhich wiper'QLl/l is standingV has no" ed all alarm conditions, as someare `more important than others and lwould call for Ya more prompt vaction' on the part .ofthe y person assigned to alleviate the trouble. T he operator will hear a ringing-current tone on each alarm number at which ihe associated alarm device is in an operated position'.

The supervising switch SS is released in this case in the hereinbetore-described vmanner. When the release position is reached, oli'- normal relay 231 falls back and againkconnects relay 233m` conductor 246 but conductor 246 has been ungrounded by the abovementioned operationot' relay 251, witl abe result that the alarm condition does not again display 'on the operating trunkuntil the trouble has beencleared Vand another alarm condition has occurred.

y @alltag subscribe/rs Zines 'through the Supery vering switch .The operator nay at one time or another haveoccasionY to callv one oit the lines over the operating trunk so that she herself may get into communication with a fcertainsubscriber. Assuming that the operator wishes to do. this, she operates the ringing. key connected in the operating trunk just to the right ci the repeating coil R-L' projecting ringing current'out over the operating trunk. vVhcn this Vis done the ringing current is -repeatcd through the repeating coil R-2 and passes through contacts of relay 202 to the lower winding of the ring-up relay'23flof the supervising switch SS. Relay 231i operates and locks itself to conductor `247, whereupon the finder F is caused to 'operate and extend a connection to the supervising switch inthe hereinbeiore described manner."

-When the -upper armature. ot relay 234- grounds the conductor extendingto wipers 2M, relay Y23S Voperates through contacts of relays 231 and 232 to place a ringing-current toneon the' line-to inform VVthe operator that she is now connected to the operating trunk.

It will be noted that relay 2Min every case, upon operating, removes the ground' from conduct-or 278 which is the common source of stopV conductor potential for the various connectors; By this arrangement, thesupervising switch is given precedenceover calls by subscribers so that the operator may be` 'subscribers line inV` the usual manner.

rinformed immediately in case of an abnormal 4condition in the exchange or shemayV have the f 1ight ot' way in case she desires to call over the operating trunk.

. Having-operated her ringing key, the op-f eratorwaits until the call lamp lights, whereupon she operates her answering key and proceeds to dial the vdigits in the Vnumber of the The first eight levels -on the connectors are multiple directly to the first eight levels on the supervisory switch, it being assumed th there are not more than eighty lines in the semiautomatic exchange. That being the case, the operator merely dials the first two digi ly on the desired'line The operator has Vknowledge of the assigned codesand she operates her special-release key in accordance with the co-de assigned to the desiredsubscriber on the called line. Each operation of the special-release keyresults in an energizetion of relay 203, Fig. 2. Relay`203 grounds the lower wiper 245 of thesupervising switch to afford a return pathl :tory the ringing current, and at its upper armature it removes the shunt from ground around the ring back condenser 207 and connects wiper 210 to a source of ringing current through the upper contacts of off-normal relay 231 and l through the ninth-level contacts 247 'The ringing circuit is taken through normally-open contacts on the olf-normal relay 231 s o as to prevent an application of ringing currentto a connector when the'operator is releasing al connector after she has dialled the wrong number, as pointed out hereinbefore. l The ninth-level contacts are provided so that no ringing current will be applied when an operator releases a connector seized by thesupervisory switch while she is supervising the connectors.

After the operator hasobtained the response on the called line and has completed her conversation she releases' the supervisory switch by operating her release key in the usual manner.v

VVhat-is claimed is: f y

1. In'a telephone system,a telephone exchange terminating magneto lines, automatic switching mechanism in said exchange for eX- -tending connections from said lines, means responsive to a flow of current from the magneto generator on a callingline for preparing said mechanism to extend the connection from such line, means for thereafter setting up a flow of direct current over said calling line, and means controlled by said flow for maintaining the extended connection.

. 2. `In a telephone system, means including automatic switching mechanism in a telephone exchange for vextending connections `from lines entering'V said exchano'e, asource *of current on each line, a source or current in the exchange, meansvresponsive to current flow froml the currentsourceon a calling ts in a. number, setting .the supervisory switch directlineffor preparingfsaid mechanism for oper-,- ation to yextend said line; means f=fordirec; tivelyfextending the Acallingline independent of further flow of' currentfrom the souceondthe callingv line, and means Vresponsive. 5to curl rent fiow over said Vline from the sourcezat they exchange tonmaintaining the connection, after it is extended. I 3. In 'a telephone system, linesgterminating at a certral exchange, a currentsource on each line, a ,currentl s-ourcefat the. exchange, trunk llines inthe exchange,"non-numerical switching equipmerrt,y means respcnsivewto current flow froml the"currentrsource I`ony a calling line for-operating said non-numericalj switching equipment to extend a connection `from the calli-ng lline toone of said .trunk lines, 4automatic switch-ing lequipmentwin` the 4exchange for extendingvra` connection fromthe calling line, .and `meansfcontrolled; 'currentvow from the cunrent source-atti; ex'- change over Vthe talking;` ylinetor maintaining the connection ateryit is extended A through vfsaid automatic' switching? mechanism@ 25.' 1l. VIna .telephonesystenn a plurali-tyet` linee entering wa cent-ral exchange.l a 'cur-renty source on each line', a current source' at the exchange, automatic 4 directive rswitches said exchange, non-numerical 'fsw'tchingff mechanism in Ysaid exc hange,v means lzrek'sfponv sive to current flowifrom thejsourceon agcalling line` for oper-ating said nonnumerical switching mechanism "to extendaconnectionjv phonefex-change systemin lwhich anfop rat-V fromk such callingli-neto one ofsaidf directive. switches, means for operatingV gthe .seized 0-directive switch .to` extend a. connection from;y the calling- `linelfand meansfcont'rolledby cur rentilow over the calling .line from the sourcef at the exchange .for` mailntainingfsaid auto-A matic switcliin itssetpositionfatter it has beenoperate l Inl-a telephone system inilwhichyconne'f; tions from; lines are extended autnaticY switching mechanism; lines".normallyvftree 4 5.

from, connections vtojacjtive. sources ofcurrent, means ici-irtransf ittingan alter h n' Y rent over :any line Vto .the centra y yjexc'ha--nge ,"V means responsive to said .altern current for .connectng the` vline with. one `o said edito-g"Y matic switches,A and a @current sour-ce associa-` 5 u ltedpwith the connectedautomatic .switch tor ,l producinga. current flow over tl ejcalling;A line. v l

i gnaa telephonesystem,subscriberslinesl` each comprising a pair". oftalking. conductors', eachccnductor beingnormallyfreeof poten-11 g tial a centralfexchange at which said linesterminate, yand means under control otaisubf.

scriber onone offsaid lines .and controlled over such'linefor placing a source ofpoten, tial on one of the conductors thereofV at the l central exchange. n

7.v In `a pajty-linetelephone system" in the partylines maybe extended by direc--` V65 tively-controlled automatici'switches; linzfaV directivelycontrolled automatic `switch{ }na non-:nume fical, switching equipment for com- 3f :piet-ing .connections between) saidl callingl 'ating trunkatthe will of.l the operator attheff dividualtofsaid voperating tnunka i switch under fthe controlloi` any subscriber on fa partyfline'orfconnecting his l`line .with ai the -ex1changej,jand lmeans also under the f con trol otfsaiid subscriber v4for.signalling:and-com versingfwith odierfr subscribers 'on the k1same?-v linewithout `causing such line to vbeconnected with switchigin the centrall exchange." Y 8. In a telephone system, magneto linesy entering a .telephone exchange ,wherein autof matic .switchingv equipment is provided- :fori extending connections f from calling. lines,

lines andautomatic fsfwitches,` `means respon sive-tothe operation of ama-gneto 'generator on .a 'callingline for operating said'non-nue.;

merical'switcl'ing means to connect-.such linev with; an automatic switch, means :responsiveg .to thev subsequentremoval;oit .the receiverion f the'calli'ng station: foiisettingupafholding l. circuit over 'thei llne for mamtaining @said non-numerical s'witchinfbrnfieans.` operated 'ya'.

preliminaryfholding circuit 'eiectivefprioi to' Vthe removal kof* the receiver7 and VImeans,-l ne'spcnsive to; the subsequent operation fof Vsaid automatic switch for opening" saidgprel' liminary holding circuit,'leavingthefhold n ofwthe non-numerical.switching'mechants l' under the control 'of theqcalling-line.

ating point.

and itor-signallingthe operator latthe 'oper-" :10. In remettez-.control semitautomaticlf telephonefexchange' system in which an olp'erg '13150 'atingtrunkis' provlde'd'between asemiaiitov matic 1" exchange f and .a centrolliiizgjfpoint', fa. Y

supervising] switch il,idividualgv tof "the said; Operating trunkifmeans responsive to 'anfabj ,l l normal condition; .in` said semi-automatic {exf 1lf5 changey for placing-:said supervising switch? under thecontrol otsai'doperating .trunk-Y and v for'signallingl rthe operator at the fconr,

trolling point7 fand means v1contro'lled'.frein f the operating pointforfplacing'. said supervisory. .Switch under theV control of: theo-pei*- change; system lfin" whichfthe automatic 125,l f vsvvitchesniii a semi`autonflzmticexchangeareV V` v ,remotely vcontrolled l`i`roman op'eratingxp ointV over an operatingtrunk,.a iinder switch n-Y nd liav accessfto the-automatic vT05 1 -underthecontrol ofwsaidoperaiting l ini? ' Y atl the operating point may intermittently inv automatic' exchange, aY 'supervising switch also individual to said operating trunk and accessible tosaid finder switch, means responsive to a callar'riving at one of vsaid' automaticV switches for operating said finder switch to` connect withY suchl automatic switch, and means responsive tofan abnormal condition arising in the semi-automatic exchange for operating Vsaid `finder switch to connect the operating trunk withsaid supervising switc -Y 12.- In` a semi-automatic telephone exchange Vsystem in which the automatic switches in a semi-automatic exchange are remotely controlled from an operating point overan operating trunk, a finder switch individual to said operating trunk and having access to the automatic switches in the semiautomatic exchange, a supervising switch also individual to said operating trunkV and accessible to said finder switch, means responsive. toa call arriving at one oi saidautol maticV switches fork operating said iinder switch tol connectY with Asuch automatic switch, means responsive to. an abnormal condition arising in theV semi-automatic exchange for operating said. finder switch toY connect the operating trunk with said supervising switch, and means for signalling the operator and for placing a 'distinctive tone on the operating trunk to vindicate to the operator that the operating trunlris con; nectedwith the supervisory switch.

13. InV a remote-control semiautomatic telephone-exchange system lwherein an operating trunk connects a semi-automatic exchange with the operating point, a supervising switchcontrolled Y over said operating trunk, and Vmeans for operating said supervising switch to supervise various portions of equipment in th'e'semi-autoinatic exchange and for operating said supervising switfc'htoV make direct connections betweentlie operating trunk and anyone of nating in the exchange.v s 14:', In 'a change systenrof theremote-control 'type wherein anoperating trunlrconn'ects the operating pointl with each, remote semi-automatic exchange, terminating equipment at the operating pointV for each operating trunk,

circuitl arrangements wliereby'the operator terrupt a Vlowof currentY over the operating Y `eluded in said terminating equipment for interrupting the current flow forsui'licientV length of timetocausethe operating trunk switchboard, means for extendinga connecv,tionrtosaid switchboard andfor setting up the lines termisemifautomatic telephone-ex-V trunlr to establisha connection in, asemi-Y automatic exchange, a slow-actingV device-in-V a'rlow ofl direct current over the trunk line through which ,theY connection is extended, s'

means responsive toa cessation of current flow over said trunk line of a predeterminedv interval for releasing the extended connection,`and a timing device operated at the will of 'the operator at said switchboard for producing such interruption. Vj

y16. In a telephone system wherein connections are automatically extended to an operators switchboard and are subsequently brokenfby a .prolonged cessation ot'current flow Vover a control circuit, a. slow acting relay at said switchboard, an operators key, and means responsive to ainoi'nentary manipulation oisaid key by the operator for operating and releasing said slow acting relay to produce the said interruption of current flow inthev control circuit. p'

17. AIna-telephone system in which connec- .mechanism located at a central exchange, in' which the switching mechanism. is prepared for operation'by current flowY from a currentl source on a callingline,'and in which the centml-exchange battery has one polegro'unded,

Yconnections/from the poles of the battery to vthe conductors, respectively, of a prepared 'extend the connection, andmeans responsive thereto for rendering the maintenance otthe" connection,v betweenV the line andthe switch dependent upon current flow over said line.

19. Ina telephone'system, an automatic switch,gmeans` for extending a connection trom' a subscriberls'line to said switch and a5 Y, tions are set up through automatic switching n for maintainingV said'connection established independent otcurrent How over said line,

means for opera-tingsaid switch to further ex,dtend the connection, saidswitch having a nor-v malposition from which it is moved to brin about saidextension of the connectiom an means responsive to the removal of said switch from its normal position for rendering', the maintenance of the connection between thelinev and the switch V'dependent upon cur- 4 rent tlow-` over thepline. Y

20. In a semi-automaticmagneto telephone' system, an automatic switch ina magneto ex change, means responsive to an application of alternating current to aline entering said ex` change for effecting a* connection between such line and saidswitch,-a'localholdingcircuit vautomatically'A established when the conf iis imam@ nectioii is made, means responsive to the'subf sequent removal of the receiver at a suhstal tionv on the line for setting up acuirent ilowy over said line from the switch, means responl sive tosaid current How yfor maintaining the connection, means -for signalling thesemi-'automatic operator when the connection is established, and means controlled by the semi? automatic operator for opening the said local holding circuit.

21.1 In a seminutomatic magneto telephone system, an automatic switch in a magneto exchange, means responsive toan application of alternating current to aline entering said exchange for extending a connectionbetween such line and said switch, a local holding circuit automatically established when the connection is made, means` responsive to the rel moval of a receiver at a substation on the line for ysetting up a. lcurrent flow over said line fromgthe switcln'means responsive to vsaid current .flow orV maintaining the connection, meansfor signalling the semi-automatic operator lwhen the connection is established, means under the control of vthe semi-anton `matic operator for operating saidjswitchV toi.A `set up a connection from said line to a called g line, and means automatically operated'inci-r dentalv tothe setting up of the connection for` opening said local holding circuit. y

22. A tr'unking Vcombinationffor a telephone rexchange comprising a finder, a plurality of mtomatic` switchesA directlyaccessibleto said finder, and another automatic switch directly7 accessible to said finder andl having access to the first-namedautomatic switches. y

23; In a semi-automatictelephone'system wherein a semi-automatic exchange is vremotely operated over an operating trunkl froml a control point, a finder in said semiautomatic exchange in which said operating trunk' terminates, aV plurality of automatic switches directly accessible to saidiinder, an-

other automatic switch directly accessiblelto said finder and having accessrto .thefirst named automatic switches, and means'o-r opi lerating said iinder independent of controlv oversaid operating trunlrto connect Vsaid operat'ingftrunlr to any predetermined'one of said l.automatic switches;

Y 24; In a semi-automatic telephone system wherein a semi-automatic exchange is re- Vinlotely' operated over an yoperatingtrunk from a control point,A afinder in saidsemiautomatic exchangein which said operating vtrunk terminates, a plurality ofautomatic switches directly accessible to said finder, an-

other automatic switch directly *accessibleto said finder and having accesstoy the first named automatic switches, means for operatf.

f S ing said finder independentof control over. vsaid operating trunk to connectsaid operat trunkto any ypredetermined,one of said automatic switches, and means` controlled 27;y Inlalineswi-tchca line vrelay having'. i opferating-circuruandi-fa, lock-ing circuit; auf` over@thefoperatingftrunk lfooperating said i l automaticswitches-directly accessibledto sand'er, :another automaticrswitch;xdirectly acfg-z i cessiblel te said .finde-r, l'iav'ili1ij v-`- access to: fsaidi first automatic switches, andV sub'scribersf,lY lines directly `acces'sible:ft-o, all'gof lsaid w auto-l mat-ic'switches.fy

526v Intelephonefsystemwliereirr connee y Y ti-onsfaregfsetup gtr-omV calling lin-.es to called g lines-fc through automatic. y. directivelyfcon? A trolledswitchea-a lineswitch terminatin' a subscribers line and'having accessi te` a arrangement Iforfautornatic;,`

exchanges'i'includingfaffinden, a Ypluralityeff rality'` `caf autofinatiov'switches, al line relays associated line, a lockingcircuit; for the other.

`o-tlier winding of 'theline relay oper-atiiig lmagnet having; a circuit closed bythe line relay, and contacts operated-bythe circuit. Ev

ing trunk is provided between the semi-autotr'olled by the operator over the 'controltrunlr semi-automatic exchange v,for placing` said Vsupervis'ii'ig switch under thecontrol offsaid ng -,trunk and for signallingy the Opf.

operat crater-jat theoperating point.

operating-cma-gnet for i opening the locking y y s28p. IngaJ remoteL-contrcl semi-automaticiteli-i'.100 l f ephone-exchangesysteminwhich anV operatl Vmatic exchange and the remote control point, ya supervising switch arranged to be con- 105` fto"supervise existing connections, and means responsiveA to an abnormal condition in said 29; In a semi-automatic exchange wherein the automatic switches are remotely controlled from a remote ,pointvover an operat ing trunlga supervising switch in the semi-5V automatic exchange arranged solas to enable the operator to supervise the automatic switches over said operating trunk, said supervising switch being normally disconnected from said operating trunk, andineans lcon-` trolled by an abnormal condition in thesemi-A lauf automatic exchange tor'connecting saidsupervising lswitchto the operating trunk.V

30;I In atelephone systemwherein a 'semi-l automatic exchangeis remotely operated over an operating'trunk from a controlstation,aplurality ofautomatic switches in said Y.

semi-automatic` exchange, subscribersrlines accessible `to said automatic switches, a super- -vising vswitch-having access to saidautomatic Switehes and to said 'sulosoriberjs lines,V means for' connectingV said supervising switch With said operating trunk toiplaoe it under the oon-V trol of the operatorjat the `oontrol station,A

u means ysaid semi-automaticV exohangefor initiating theoperatlon of's'aid connecting l the automatierswitches are controlled from a means, and means at the control station for initiating lthe operationof said-connecting mean/s.

31In aI-.semi-automatic exchange wherein remote station overan operating trunk, a supervising switch in the semi-automatic eX- ,ohange arranged so as to enable the operator at the vzontrol station to supervise the autov matie switches overthe operating trunk; said vsupervising switch being "normally "discon-A neoted from said operating trunk, and means y for connecting said supervising switch to said operatmgtrnnk. f 32.1I`n a semi-automatic exchange wherein l the automatic switches are controlled from a remote stationover'an operating trunk, a

change arranged so as to enable' the operator to supervise the automaticswitolies over said V operating trunk," saidlsupervising switch bemy name this 2 35" 'ing normally disconne'ote'dfrom said operating trunk7 andmeans controlled over the operating trunk from the remote station for connecting said-supervising switch to said Y operatingtrunk; Y Y

VVIn Witness whereof, 'I' hereunto subsoribe 9th day of November, A. D;

1921;'. Y LEONARD L. RUGGLES.

or i supervising! S'Witeh in the semi-automatic exi f 

